To address wayfinding difficulties and physical activity among cognitively-impaired older adults, we propose to develop a navigation aid that can be attached to three- and four-wheeled rollators. The navigation aid will provide navigation assistance to the user and will track the user's movements for later analysis by caregivers. Navigation assistance will be provided in the form of verbal and visual instructions that guide the user to a desired location. Information about the user's movement that will be stored will include time and distance of individual "trips" and the path that was followed. Using this information, caregivers will be able to identify changes in the amount of activity a user engages in, speed of travel along frequently-traveled routes, and mistakes made during navigation. The specific aims that will be pursued during the course of this project are: To construct a prototype of the system using "off the shelf components; To implement navigation assistance software which provides verbal and visual instructions that guide the user to a target location; To evaluate the technical feasibility of the system through laboratory tests; To evaluate the clinical feasibility of the system with the assistance of potential users and clinicians through focus groups and field trials. The prototype developed during Phase I will consist of a four-wheeled rollator that is able to determine its location in a known environment using a digital compass and RFID transmitter/receiver. This prototype will be evaluated for technical and clinical feasibility through focus groups, lab tests, and preliminary field trials involving caregivers and elderly users. Phase II activities will include refining the prototype, implementing software for analyzing the activity level of the user, and testing the system extensively with potential users.